More Hope for the Devil

credit: Devil Ark

US Person has been following the struggle of the Tasmanian Devil species (Sarcophilus harrisii) to survive the fatal spread of a contagious cancer. Humans trying to help the marsupial in its plight have resorted to a quarantine of healthy animals on the mainland as a genetic reservoir. The disease has devastated all of Tasmania's endangered devil population with sightings of the marsupial down by 85%. Only the second contagious form of cancer known to science (the other infects dogs) it is transmitted by bites from an infected devil. Often these occur on the face in territorial and mating fights resulting in hideous facial tumors. The disease is 100% fatal in a matter of months.

Scientists first thought the lack of devil genetic diversity played a role in their immune system's inability to detect invading tumor cells. However, a consortium of universities studying the problem have made an important discovery. Their published research says devil cancer cells lack histocompatiblity complex cells (MHC) that are present on the surface of nearly every mammalian cell. Because the tumor cells do not have these molecules, they avoid detection by the devils' immune system. Tumor cells still have the genetic code for these molecules but it is suppressed. When proteins that trigger immune response such as interferon-gamma are introduced, the tumor cells are forced to express MHC molecules. Scientists involved in the research hope the discovery will provide a pathway to developing a vaccine for the devils. Obstacles to a cure remain because the cancer is evolving rapidly and vaccinating a wild population like the feisty devil is not an easy task. The research goes on because devils need human help to survive the deadly plague, but study has human implications too since it is only a matter of time before a human strain of contagious cancer emerges from the invisible world.